Pharmacy benefit managers generally provide prescription drug programs for clients that may, for example, sponsor drug benefit programs for members. As part of the providing the prescription drug programs for clients, pharmacy benefit managers (PBM's) may adjudicate claims from pharmacies for prescriptions filled by members at various pharmacies. The PBM may also reimburse the pharmacies for prescriptions obtained by members at the pharmacies. The PBM may also bill clients for the cost of prescriptions adjudicated by the pharmacy benefit manager.